Featured Research

The genetic intricacies of salmon sexes and the apparent effects of pollution on both Puget Sound and Lake Mead fishes were among topics reported on by scientists gathered here this week for a symposium on salmon recovery.

Share This

MOSCOW, Idaho – The genetic intricacies of salmon sexes and the apparent effects of pollution on both Puget Sound and Lake Mead fishes were among topics reported on by scientists gathered here this week for a symposium on salmon recovery.

Related Articles

Sponsored by the University of Idaho – Washington State University Center for Reproductive Biology and the National Marine Fisheries Service Northwest Fisheries Center in Seattle, the symposium drew nearly 70 scientists primarily from the Northwest.

Researchers from universities and tribal, federal and state fisheries departments spent two days reviewing the question of whether pollution in popular waters is affecting fish reproduction, salmon genetics and conservation efforts.

In Las Vegas Bay, an arm of Lake Mead that is fed by 130 million gallons of treated sewage and other contaminated industrial runoff, U.S. Geological Survey scientist Steven Goodbred reported on an extensive study of carp, razorback suckers and largemouth bass.

That work, among the longest running studies of its kind ever undertaken, did find evidence that the fishes showed reduced levels of sex hormones, primarily testosterone.

The result is that both the development of male fish and sperm quality is reduced in fish found in Las Vegas Bay, Goodbred said.

Lyndal Johnson, a National Marine Fisheries Service scientist at Seattle, reported on work in Puget Sound. She said the agency found a strong correlation between abnormal levels of a sex hormone derivative in English sole and the fishes’ proximity to major sewage outfalls.

The study sampled areas ranging from heavily developed Elliott Bay near Seattle to near pristine Hood Canal.

University of British Columbia scientist Luis Afonso reported that tests with young chinook salmon exposed to estrogenic compounds, undiluted bleached kraft pulp mill effluent and diluted sewage effluent did show apparent sex reversal.

They reported their findings during a session led by James Nagler, a UI assistant professor of biology, who sampled fall chinook from the Columbia River’s Hanford Reach. He found many of the females carried genetic markers that suggested they began life as males.

Whether that showed the fish had reversed sex early in development or were merely biological oddities remained open to speculation, Nagler said.

Nagler reported that subsequent sampling in the Hanford Reach, Yakima River and below Bonneville Dam showed the phenomenon occurred elsewhere in the basin as well but there was no apparent pattern.

WSU zoology professor Gary Thorgaard, who worked with Nagler on the original study published in late 2000, led another session about the state of the current science of salmon sex determination.

Thorgaard reported that his team at WSU is continuing to work on a definitive test. Scientists also reported during the session on their efforts to find genetic markers that indicate the genetic sex of salmon.

Other scientists from WSU, NMFS, U.S. Geological Survey and the University of British Columbia all reported their own efforts to find the still-elusive definitive genetic test for sex in salmon.

Another panel led by NMFS scientist Penny Swanson of Seattle focused on various strategies to preserve the genetic heritage of Northwest salmon runs.

Panelists included UI zoology professor and conference organizer Joseph Cloud, who reported on efforts to preserve salmon sperm by freezing it in liquid nitrogen. He also reported on work to preserve ovarian tissue from females.

Cloud reported that he and Nagler had successfully transplanted testes that had been cryogenically preserved and induced them to produce sperm. They have also transplanted frozen ovarian tissue but whether the females will produce eggs is still more than a month away.

Cloud said the conference reflects the close working relationship of UI and WSU scientists and the Center for Reproductive Biology. He said plans are in the works to establish a closer working relationship with scientists on the two campuses and the National Marine Fisheries Service Northwest Fisheries Center.

University Of Idaho. (2002, April 5). Fish Reproduction Takes High Tech Turns As Science Probes Intricacies Of Sex. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2002/04/020402074956.htm

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015 — While studying a ground-nesting bird population near El Reno, Okla., a research team found that stress during a severe weather outbreak of May 31, 2013, had manifested itself into malformations in ... full story

Mar. 3, 2015 — The 3-D printing scene, a growing favorite of do-it-yourselfers, has spread to the study of plasma physics. With a series of experiments, researchers have found that 3-D printers can be an important ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Pediatric otolaryngologists and surgeons are concerned with parents getting the wrong message regarding the safety/desirability of letting babies and young children eat peanuts to prevent them from ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Similar to humans and animals, plants possess an innate immune system that protects them from invading pathogens. Molecular structures that only occur in pathogens enable their recognition and ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Mar. 3, 2015 — To simulate chimp behavior, scientists created a computer model based on equations normally used to describe the movement of atoms and molecules in a confined space. An interdisciplinary research ... full story

Featured Videos

Rare Goblin Shark Found in Australia

AFP (Mar. 3, 2015) — A goblin shark, a rare sea creature described as an &apos;alien of the deep&apos; is found off Australia and delivered to the Australian Museum in Sydney. Duration: 01:25
Video provided by AFP

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015) — Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

Mar. 10, 2014 — While farmed salmon are genetically different to their wild counterparts, they are just as fertile. This is important information because millions of farmed salmon escape into the wild -- posing ... full story

Dec. 12, 2013 — A PhD project has investigated the use of sterile salmon in aquaculture as a means to prevent escaped farmed salmon interbreeding with wild salmon. The study used a method known as triploidy to ... full story

Jan. 15, 2013 — Mycobacteriosis in fish is a disease that is difficult to detect and therefore often underdiagnosed. For the same reason, information about the effects of this disease on the fish farming industry ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.